Input Impedance (Unbalanced)
Unbalanced input impedance is the load presented to a source by the specified unbalanced analogue line input.
The value applies to that connection, commonly RCA. It is separate from maximum signal voltage and from the impedance of a transducer driven elsewhere in the system.
Input Impedance (Unbalanced) — Equalizer
For an equalizer, this is the load presented by its unbalanced analogue input to the preceding component. Other input types can have different ratings.
Compare the same connection and frequency condition. Do not substitute a balanced-input figure or a source’s output impedance; an input-voltage limit is also a separate specification.
Input Impedance (Unbalanced) — Subwoofer
For a subwoofer, this value describes its unbalanced line-input load, normally using RCA. It is distinct from the impedance of the driver or a speaker-level input.
Compare the source connection with the matching input rating. A connector adaptor does not make input impedances identical, and this value does not establish maximum acoustic output or input sensitivity.
Input Impedance (Unbalanced) — Crossover
For an active crossover, the unbalanced input impedance describes loading on the source before the signal is divided into bands. The outputs feeding amplifiers have separate impedances.
Compare the source’s requirements with this input path and keep connector or frequency conditions attached. Do not use a value from the other input type merely because the signal can be connected through an adaptor.
Input Impedance (Unbalanced) — Power Amp
For a power amplifier, this describes the load on the source at the unbalanced input. It is separate from the load of the loudspeaker connected to the amplifier output.
Compare the source with this specific input rating rather than a value for the other connector type. Preserve any frequency or lower-bound condition, and keep input sensitivity in volts separate from impedance in ohms.
Input Impedance (Unbalanced) — Preamp
For a preamplifier, this is the load its unbalanced line input presents to the connected source. Selectable values or a stated range can describe different operating settings.
Compare the selected setting and any published range or frequency condition. Keep phono-cartridge loading separate even when both line and phono inputs use RCA sockets, and do not substitute a balanced-input rating.